VPRS 19436 Geophysical Logs

This series contains records of geophysical well-logging undertaken and/or maintained by the Geological Survey of Victoria (VA 4118). Geophysical well-logging, also called borehole logging, is a technique used to gather data about subsurface conditions and geophysical characteristics of the surrounding area. The logs are created by conducting measurements at intervals within boreholes or wells drilled into the surface of the Earth. The data collected through these logs may be used for determining hydrogeological units, ground-water quality, and oil and gas research. It is thus a valuable tool enabling geoscientists, engineers, and researchers to make informed decisions regarding resource exploration, construction planning, and environmental assessments. This type of well-logging is distinguished from geological well-logging, with the latter referring to the visual inspection of the drilled cores brought to the surface. However, the intent of the two types of well-logging is the same: to determine the structure and composition of the geologic rock layers surrounding the borehole. There are various logging techniques used to capture data and information regarding the geophysical behaviour of the borehole. Two commonly used methods are Gamma Ray Logging, which measures natural gamma radiation emitted by rock formations and aids in lithological identification and stratigraphic correlation; and Resistivity Logging, which determines the electrical resistivity of subsurface materials, helping to differentiate between different rock types and identify zones of interest.